In a liquid mixed with solid particles having larger specific gravity than the liquid, it is difficult to hold a uniformly mixed state because the solid particles precipitate with the lapse of time. Holding the uniformly mixed state requires the provision of a mixing device and continuous stirring in a vessel in which the liquid mixed with the solid particles is stored.
As commonly used mixing devices, there are the motor type in which a propeller-like member is disposed at a tip of a rod connected to a motor power shaft and is rotated for mixing in the liquid mixed with the solid particles, and the magnetic force type in which a stirrer incorporating a magnet or a magnetic body is put in the liquid mixed with the solid particles and is rotated for mixing by the action of a magnetic force exerted from the outside of the vessel.
When the liquid mixed with the solid particles is quantitatively discharged and dispensed from the vessel, a discharge device is used which is generally employed to discharge and dispense a liquid material. In the discharge device handling the liquid mixed with the solid particles, however, it is required to one of the various types of mixing devices mentioned above in order to hold the uniformly mixed state. If the liquid mixed with the solid particles is not stirred, a trouble may occur in that the liquid mixed with the solid particles is discharged in a non-uniform state, or that it cannot be discharged because of clogging of a discharge port.
A discharge device provided with a mixing device is disclosed in Patent Document 1, for example. Patent Document 1 discloses a discharge device including a vessel, a stirrer for stirring a liquid, and stirrer rotating means for rotating the stirrer by a magnetic force, wherein the stirrer is arranged at a bottom in the vessel of the discharge device that discharges the liquid, and the stirrer has a through-hole penetrating from an upper surface to a lower surface thereof, a projection is formed in the upper surface, and a groove is formed in the lower surface to communicate an outer peripheral surface of the stirrer with the through-hole.
Another example of the mixing device is disclosed in Patent Document 2. Patent Document 2 discloses a magnetic driving device comprising a drive rotating member, a driven rotating member disposed in opposing relation to the drive rotating member, drive magnets disposed on an opposing surface of the drive rotating member, and driven magnets disposed on an opposing surface of the driven rotating member in the same number as the drive magnets, wherein the drive magnets and the driven magnets have substantially the same shape and are each constituted as a both-surface 2-pole magnet having one magnetic pole formed over one entire lateral peripheral surface and the other magnetic pole formed over the other entire lateral peripheral surface, the drive magnets and the driven magnets are each attached to the corresponding rotating members such that a central extension line passing the opposing surface of the drive magnet and the opposing surface of the driven magnet are parallel to each other, and when the drive rotating member is rotated, the driven rotating member is rotated by a magnetic force. Patent Document 2 further discloses a mixing device in which the above-mentioned magnetic driving device is used as a means for stirring a liquid in the mixing tank.